$string = "now is the time for all good men to come to the aid of their country while the gratuitously extralongwordwithmorethantwentycharactersexdtendson and on.";

grep { push(@arr,substr($_,0,19)) } split (" ",$string);

print join("\n",@arr);

##</code><code>##


while ( $string =~ /(\S.{0,19})(?=\s|$)/g ) {  
     # NB: "=~" here, rather than a simple "=" in original.
  push(@arr, $1);
}

for my $arr(@arr) {
        print $arr . "\n";
}